<!doctype html> 
<html> 
<head> 
    <meta charset="utf-8"> 
    <title></title> 
</head>
<body>
<script type="text/javascript">
var c = 'wuhan';//字面量
//
function a(b){
	arguments[0] = 'wangyuechao';
	alert(b);//'wangyuechao'
};
a(c);
alert(c);//'wuhan';

</script>
</body>
</html>